Submm-bright X-ray-absorbed QSOs at z ∼ 2: insights into the coevolution of AGN and star formation

We have assembled a sample of five X-ray-absorbed and submm-luminous type 1 QSOs at z ∼ 2 which are simultaneously growing their central black holes through accretion and forming stars copiously. We present here the analysis of their rest-frame UV-to-submm spectral energy distributions (SEDs), inclu...

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Detalles Bibliográficos
Autores: Khan-Alí, Anuar, Carrera, Francisco J., Page, Matt, Stevens, J. A., Mateos, Silvia, Symeonidis, M., Cao Orjales, J. M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/140237
Acceso en línea:http://hdl.handle.net/10261/140237
Access Level:acceso abierto
Palabra clave:Galaxies: starburst
Quasars: supermassive black holes
Quasars: general
Galaxies: high-redshift
Galaxies: evolution
Galaxies: star formation
Descripción
Sumario:We have assembled a sample of five X-ray-absorbed and submm-luminous type 1 QSOs at z ∼ 2 which are simultaneously growing their central black holes through accretion and forming stars copiously. We present here the analysis of their rest-frame UV-to-submm spectral energy distributions (SEDs), including new Herschel data. Both AGN (direct and reprocessed) and star formation (SF) emission are needed to model their SEDs. From the SEDs and their UV–optical spectra we have estimated the masses of their black holes MBH ∼ 109–1010 M⊙, their intrinsic AGN bolometric luminosities LBOL ∼ (0.8–20) × 1013 L⊙, Eddington ratios LBOL/LEdd ∼ 0.1–1.1 and bolometric corrections LBOL/LX,2−10∼30−500LBOL/LX,2−10∼30−500. These values are common among optically and X-ray-selected type 1 QSOs (except for RX J1249), except for the bolometric corrections, which are higher. These objects show very high far-infrared luminosities LFIR ∼ (2–8) × 1012 M⊙ and star formation rates SFR ∼1000 M⊙ yr−1. From their LFIR and the shape of their FIR–submm emission we have estimated star-forming dust masses of MDUST ∼ 109 M⊙. We have found evidence of a tentative correlation between the gas column densities of the ionized absorbers detected in X-ray (NHionNHion) and SFR. Our computed black hole masses are amongst the most massive known.